


I'll be Alpha

by kettlepillow



Category: Sherlock (TV)
Genre: Alpha Mycroft, Alpha/Beta/Omega Dynamics, Anal Sex, BAMF Mycroft, Begging, Knotting, M/M, Mating Cycles/In Heat, Multiple Orgasms, Mycroft Being a Good Brother, Omega Sherlock, Possessive Behavior, Protective Mycroft, Riding, Size Kink
Language: English
Status: Completed
Published: 2015-03-13
Updated: 2015-03-13
Packaged: 2018-03-17 16:53:14
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,838
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3536942
Author URL: https://archiveofourown.org/users/kettlepillow/pseuds/kettlepillow
Summary: <blockquote class="userstuff">
              <p>Might aswell ask the guy to come up. - SH<br/>Mycroft's pulse sped up. What guy? - MH<br/>There's an Alpha throwing himself against the front door. Full blown heat is close I guess. Haven't had one for so long, hard to tell. - SH<br/>The older Holmes was on his feet.<br/>Don't you dare! - MH</p>
            </blockquote>





	I'll be Alpha

Judging by the dampness of my thights, my heat is coming up earlier. - SH

Mycroft Holmes started coughing violently. Sitting in one of the Diogenes' quiet rooms made it sound earth shakingly loud and earned him side eyes from other club members. He sat down his tea, rereading the text through teary eyes.

To what exactly do I owe this piece of information? - MH

There was a long pause.

Supressants won't work anymore. I fear for my sanity Mycroft! - SH

Mycroft sighed.

You're not alone with that, I'm affraid. - MH

Silence.

Whenever Mycroft received a text from him, he knew Sherlock was completely out of his depth.

Normally the Omega was on strong suppressants as soon as his biology made advances to take over. Very predictable. Every once in a while Sherlock's scent would disappear completely then, making Mycroft's Alpha-self cringe unintentionally. It simply wasn't natural. An Omega his age was supposed to have a settled life or at least a mate.

The other part of Mycroft knew, that was nothing Sherlock would even consider. Relationships were not his area. The only person Sherlock opened up to in moments like this was Mycroft.

Family was all they both had in the end.

If he was completely honest with himself, he couldn't imagine Sherlock coming to someone else for help. He didn't want to lose this burden. Of course his brother could never know. It wasn't his decision to make.

Two hours later there was another message.

Might aswell ask the guy to come up. - SH

Mycroft's pulse sped up.

What guy? - MH

There's an Alpha throwing himself against the front door. Full blown heat is close I guess. Haven't had one for so long, hard to tell. - SH

The older Holmes was on his feet.

Don't you dare! - MH

He was outside and furious.

I nneeed it! - SH

 

Mycroft gritted his teeth. He had sworn himself to never ever let his brain get out of his control, to never interfere in anything regarding Sherlock's pitiful biology.

But all he could see was a pack of Alpha's trying to mount his brother.

It was enough.

 

His vision went red and when the car stopped at 221B Baker Street Mycroft was a dominant Alpha. Determined to protect and claim. Nothing else mattered.

There was a small group of people right in front of the door.

Mycroft walked faster.

They fought to get closer to the entrance. Not just arguing. Far beyond rational they threw themselves at each other to put their rivals out of action.

The older Holmes raised his umbrella and dealed one of them a blow. He could smell pain replacing the strong Alpha musk before they went boneless.

The others had smelled it too and stopped in their motions when Mycroft grabbed the door knob and produced a key from his pocket.

His voice was a mere whisper.

"This is my teretory. Everyone invading it dies."

 

 

Mycroft slammed the door and ran up the stairs.

Oh.

It was only then that the sweet scent of heat hit him with full force. All the blood rushed to his groin. Combined with a good dose of adrenaline, an ultimate Alpha- cocktail flooded his veins.

Sherlock.

Within seconds Mycroft was outside Sherlock’s bedroom door, the heavy smell oozing from every tiniest crack in the wood.  
It was locked.

 

"Let me in." The Alpha’s voice was calm and steady. He had to do this right. Even though his stiff member screamed at him to break down the last barrier.  
"Mycroft?“, came Sherlock’s deep voice. "What are you doing here?"  
"Let me in and I'll tell you.", he tried.  
"No."

Sweat started trickling down the Alpha's temples.

"I beat the others down. I protected you! We can get through this together."

The scent of heat was mixed with a feeling of protection.  
He feels safe.

"You'll fuck me like a beast."

Mycroft rested his head against the door frame, closing his eyes. He was so hard it hurt.

"Is that what you want?"

Sherlock moved. The new wave of arousal was answer enough.

He whispered:  
"You're my brother."

"Do you want me to make it better? Do you want me to give what I can provide?"  
His cock throbbed, underlining his intentions.

The Omega opened the door.

His pupils were blown wide, the dark curls even messier than usual. Sherlock wore nothing but his own lubricant.

Mycroft twitched in excitement. He stepped closer.

The two men were as close as possible. Mycroft's musk cocooning them.

Slowly, so slowly, Mycroft dared to bring his nose to Sherlock's jawline. 

The Omega groaned. He bared his ivory throat. 

The Alpha chuckled and started scenting, while taking small steps towards the bed. Sherlock had to follow his lead. Backwards. It was like a seductive tango.

 

When they reached the bed Sherlock lowered himself onto his back. His brother followed, crawling up between spread thighs, not letting his eyes wander from what was always ment to be his.

 

He freed his raging erection.

 

The Alpha felt victorious. He had protected and claimed and was about to fulfill his purpose.  
He got rid of his shoes and jacket while nibbling at Sherlock's jaw. As he did so, Sherlock saw Mycroft's penis for the first time  
and said jaw dropped.

Sherlock looked at him as if he were an arch angel. His hormone addled brain wanted to worship his length.

"Please.", he sobbed. " Need your fucker."

 

Mycroft licked one long stripe from Sherlock's navel to the lubricating hole. The Omega's readiness filled the room. His body begged for a knot.

"Open your legs, for me.", came the Alpha's voice like velvet. "Wider."

Sherlock's legs fell apart, allowing Mycroft to rubb his glans against him.

He pushed in.

Sherlock almost lost consciousness. The head alone was stretching him painfully wide. He could feel the knot already swelling.

"Move!"

The other man began to move. His face burried in the Omega's neck. 

"Going. To. Breed.", he gave one hard thrust." You."

Sherlock's breath came too shallow. 

Fear.

Mycroft started nuzzling his jaw.

Sooth.

The knot settled deep inside Sherlock's body, who went boneless beneath him.

Suddenly all his inner walls squeezed at the cock spreading him open.  
He started shaking and released a small splash of cum onto his own belly.

It was enough to push Mycroft over the edge. 

His knot started pulsing and they both moaned.

Mycroft collapsed, qickly spooning his Omega to make sure their internal connection was unharmed.

Silence.

Every few seconds Mycroft's cock twitched to release more seed. The knot kept it Sherlock, who was taking it in with giant need.

"Filling me with your white gold, aren't you?" 

"Certainly."

 

Mycroft woke and realized he was still balls deep inside his brother, even though the shaft had deflated.

Sherlock was asleep, but pheromones for a second go hung in the air. He was immediately hard again.

The older Holmes tried to pull out, but as soon as he moved, Sherlock squirmed against him.

"Need another round?", Mycroft asked.

Sherlock nodded. His face was flushed as he turned around a little, new lubricant started leaking from between his legs. 

Mycroft rolled over and Sherlock braced himself on his forearms. 

"I'm still so full of you. Yet I crave you again." It almost sounded miserable.

The older man smiled. 

"It's nothing to be ashamed of, brother."

His cock throbbed. 

Sherlock felt magnificent. Hot and tight and full of him.

He moved slowly. Without haste. This time, it was all about Sherlock's release.

Sherlock started making soft noises of pleasure.

The prostate.  
Mycroft chuckled:  
"That's the sweet spot, isn't it?"

He grasped the Omega's erection. Stroking in time with his own thrusts.

He could feel Sherlock's muscles tense.  
"Yeeeesssss."  
Sherlock's arms gave in and he melted against the pillows, coming over his brothers' fingers.

Mycroft pulled out and began working his own erection hard, almost violently. Using Sherlock's cum to lube him further.

He orgasmed without making a sound, his cum splattered over Sherlock's ass.

His brother gasped.

Deep inside him, something told the Alpha to mark what was his.  
So he rubbed the white, hot liquid into Sherlock's skin.

"Now everyone will know that you've been claimed…and mounted…and satisfied.", he murmured, scenting his work.

The urgency was gone from Sherlock's odour.

He pulled his brother down and embraced him tightly. They fell asleep in total sync.

 

The next time Mycroft opened his eyes, Sherlock's face was only inches away from his own.

"I want to sit on your dick.", he said, watching his brother through half closed lids.

Mycroft was pretty sure he'd never need another wank fantasy in his life.

The Alpha's body responded with a strong, fertile bouguet.  
He was no longer ruler over his needs. Again.

He nodded slowly. Not trusting his own voice.

"Lay back.", said his brother as he admired the newly stiffened cock. It was shaped to be inside a needy ass. Flushed red and leaking eagerly.  
The Alpha's stamina seemed unlimited.

 

It felt so good to be Mycroft's top priority. How he could make him forget all his duties with one sentence.

Sherlock sank down.  
Stretched from earlier, the pain was bareable. Bit by bit he worked himself further.

Mycroft supported his hips and tried very hard not to hurt him by rocking back.

 

"So full.", sighed Sherlock. His body welcomed Mycroft home and finally he was fully settled.

"That's just what your needy ass askes for. I can smell it. That's the heat."

 

Sherlock burried his face in both hands. He nodded. The sensation was new. Never before had it been so deep.

He lifted himself off the shaft and sank down again. Only leaving the head inside. It felt agonizing good. Heat was exhausting. But he craved it.

 

When Mycroft held him by his hips, Sherlock started riding it in earnest.

 

For some time there was only the sound of skin slapping against skin and heavy breathing.

 

Sherlock bounced properly on his Alpha's cock. Head thrown back, eyes shut tightly and biting his bottom lip.

"Oh god, please! Where's your knot?", he whined.

 

Mycroft's knot swell. 

He couldn't hold back and pounded into Sherlock until it was too big to move. Until Sherlock could only sit on top of him and watch him with wide eyes as the Alpha cried out and pulled him close.  
His womb took in the huge ammount of sperm flooding his ass.

They rode it out and waited in quiet bliss.

 

Afterwards, Sherlock's heat eased out. His scent became less prominent.

 

"Do you think I'm carrying your child?", he asked.

"Unlikely.", said the Alpha. " Heat hormones can trigger sibblings, but an impregnation is basically unheard of.

Sherlock's Omega-self was just the tiniest bit disappointed.

 

"Shower?", he suggested.

Before Sherlock stood up he turned to look his older brother in the eyes.

"Do you regret this?"

"No."

Sherlock smiled.

"Will you continue to keep me safe?", he asked softer.

Mycroft brought his lips close to Sherlock's ear.

"Your loss would break my heart."


End file.
